I had to go somewhere else to test it, as we do not have any rain here in the south of France for a long time…
Went to Switzerland for the Swizzeridoo festival and had lots of rain, but did not have to use the whiper at all!

Window stays clean!

So if you are looking for a solution, here it is!

Part number 9400.E9
Official Citroën (PSA) part, that fits on the P107 (ref.: 9614X4) also
It is made for PSA by Car Styling Belgium.
Has to be painted in the colour of your car and is glued on the hinges with a special glue that comes in a packedge ref.: 9799G1 (glue and cleaner)

For prices in France:
 

Manual (pdf)  for mounting:
Notice de Montage